Is Plotly.js Free?
Can I use Plotly.js without signing up to any service?
Yes. You can use Plotly.js to make, view, and distribute charts and maps without registering for any service, obtaining any token, or creating any account. The one exception is that to view tile maps which use tiles from the Mapbox service (which is optional, as you can use other tile servers), you will need to have a Mapbox token.
Can I use Plotly.js offline, without being connected to the internet?
Yes. You can use Plotly.js to make, view, and distribute graphics totally offline. The one exception is that to view tile maps which use tiles from a cloud-hosted service, such as Open Street Maps or Mapbox, you will need a connection to that service. You can view tile maps totally offline if you run your own local tile server and use its tiles.
Is Dash free?
Yes. Plotly's Dash analytics application framework is also free and open-source software, licensed under the MIT license.